Ore concentration.



UNITED STATES PATENT OFFICE.

HENRY HOWARD GREENWAY, 0F CLARE, SOUTH AUSTRALIA, ,AIND ALFRED HENRYPIPER LOWRY, 0F PRAHRAN, VICTORIA, AUSTRALIA.

our: CONCENTRATION. I

No Drawing.

To all whom it may concern Be it known that we, HENRY HOWARD GREENWAY,analytical chemist and metallurgist, of Clare, State of South Australia,Commonwealth 34 Queen street, Melbourne, State of Victoria, Commonwealthof Australia, and AL- rano HENRY PIPER LOWRY, metallurgist, of Lynzala,Highstreet, Prahran, State of Victoria aforesaid, have invented certainnew and useful Improvements in ()re Goncentration, of which thefollowing is a specification.

This invention'relates to improvements in ore concentration and has forits object the separationof various metallic snlfids from each other bymeans of flotation separation.

In this specification theword ores is intended to include concentrates,tailings slimes or other products containing mixed metallic sulfids.

\Ve have discovered that if. a salt of chromium (such as sodiumbichromate or potassium bichromate) is introduced in solution into thecircuit liquors, or if the material to be treated is subjected to theaction of such chromium salt solution by digestion or otherwise that thesulfids are afiected in such a way as to leave certain of them amenableto flotation separation while certain other of them are renderedrelatively not amenable to flotation whereby products are obtainedrelatively high in certain sulfids on the one hand and relatively highin other sultids on the other hand.

According to this invention the mixed sulfid ores after pulverizationare introduced into water containing in solution, a salt of chromium(such as sodium or potassium biehromate) and also a small percentage ofan air emulsifying agent for example an essential oil (say eucalyptus)and the mixture is thoroughly agitated and submitted to a flotationseparation, the result of which is to cause certain of the sulfids tofloat in the form of a froth or scum which can be sepa- I rated by anywell known means, leaving in the residue the other sulfids which are notsusceptible to flotation.

In some instances it may be advisable to digest the pulverized mixedsulfid ores in water containing in solution a salt of chromium (such assodium bichromate or potassium bichromate) and after removing thesurplus solution subsequently submitting the Specification of LettersPatent.

of Australia, at present ofv Patented July '7, 1914.

Application filed May 17, 1913. Serial No. 768,374.

substances referred to.

The following are examples of the application of this invention (1.) Amolybdenum ore containing 15% molybdenite and 25% iron pyrites wascrushed to pass 100 mesh, and then subjected to froth flotationtreatment in apparatus of well known type by being first of allvigorously agitated with four times its weight of water at 120 F.containing in solution 0.25% ofsodium bi'chromate to which was added.eucalyptus oilv in the proportion of one pound per ton of ore treated.The flotation product obtained from this operation consisted of aconcentrate containing 93% molybdenite and 4.9% iron pyrites.

(2.) A copper ore containing 6.5% copper and 35% iron was crushed topass 100 mesh. This was digested in a hot solution containing 1% sodiumbichromate for a period of about 30 minutes. The digest-ion liquor wasthen decanted and the material was subjected to froth flotationseparation using water only to which was added a frothing agent (viz,eucalyptus oil) in the propertion of 1 pound per ton of materialtreated, pro ducing a flotation product containing 19% copper and 30.2%iron, leaving a residue containing 0.7% copper and 36.2% iron.

(3.) A lead-zinc slime containing 18.6% lead and 32.2% zinc was digestedfor thirty minutes in warm water containing in solution 1% of sodium'bichromate. The solution was decanted and the material subjected to thefroth flotation separation using water only to which was addedeucalyptus oil in the proportion of 1 lb. per ton of slime treatedproducing a flotation product containing 47.2% zinc and 6.3% lead,leaving a residue containing 31.6% lead and 16.3% zinc.

In most instances the action is facilitated by heating the solutions,and we have found temperatures of from 120 F. to 150 F. to be in mostcases suitable.

We do not confine ourselves to the proportions above given: the bestproportion in each case can be determined by trial.

Having now fully described and ascerire tained our said invention andthe manner in which itis to be performed we declare that what we claimis v 1. A process of concentrating 'metalliferv ous ores, which consistsin subjecting the ore 'ous ores, which .consists in subjecting the oreto the action of a chromium salt and to agitation with a frothingagentto produce a froth relatively high in certain values of the ore.

3. A process of concentrating Inetallifer ous ores,,which consists insubjecting the ore to digestion in a solution of a chromium salt, andthen to flotation separation, whereby products are obtained relativelyhigh in certain values and other products are obtained relatively highin other values.

4. A process of concentrating metalliferous ores, which consists insubjecting the ore to digestion in a solution of a chromium salt, andthen to a itation with a frothing agent to produce a roth relativelyhigh in certain values of the ore..

5. A process of concentrating ores, which consists in subjecting an orecontaining zinc and lead sulfids to'the action of a chromium salt and toa flotation separation, whereby there is produced a flotation productrelatively high in zinc and low in lead and a 6. A process ofconcentrating ores, which consists in subjecting an ore containing zincand lead sulfids to the action of a chromium salt and to agitation'witha frothing agent to produce a froth relatively high in zinc and low inlead leaving a residue relatively high in lead and low in zinc.

7. A process of concentrating ores, which consists in subjecting an orecontaining zinc a salt'of chromium, and then to flotation separation,whereby a float concentrate is obtained relatively high in zinc and lowin lead and a residue is obtained relatively low in zinc and high inlead.

8.,A process of concentrating ores, which consists in subjecting an oreccntaining'zinc and lead sulfids'to digestion in a solution m a salt ofchromium, and then to agitation with a frothing agent to produce a frothrelatively high in zinc and low in lead, leaving a residue relativelylow in zinc and high in lead. v

In testimony whereof we, the said HENRY HOWARD GREENWAY and ALFRED HENRYPIPER LoWRY, have signed our names to this specification in the presenceof two subscribing witnesses.

HENRY HOWARD GREENWAY.

u ALFRED HENRY PIPER LOWRY.

WVitnesses CHARLES NICHOLAS COLLISON, Daisy \VrLLIAMs. 1

and lead sulfids to digestion in a solution of resi'due'relatively highin-leadand' low in I

